#include<iostream>
#include<algorithm>
using namespace std;
string f(long long n){
    string "";
    while(n){ n--; s+=char('A'+n%26);n/=26; }
    reverse(s.begin(),s.end());
    return s;
}
int main()
{
    int k;
    if(!(cin>>k)||(k!=1 && k!=2)){cout<<"Invalid input";return 0;}
    if(k==1){
        long long n;
        if(!(cin>>n)||n<1||n>2147483647){cout<<"Invalid input";return o;}
        cout<<f(n);
    }else{
        double x;
        if(!(cin>>x)||x<1.0||x>100000.0){cout<<"Invalid input";return 0;}
        cout<<f((long long)x);
    }
}